Mitsubishi Evolution X. Manual — part 540

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-67

DTC B2409 STL unit comm.(No response)

CAUTION

• If DTC B2409 is set, diagnose the CAN bus

lines.

• Whenever the steering lock unit is replaced,

ensure that the communication circuit is nor-
mal.

.

DTC SET CONDITION

When the ignition push switch is pressed, the steer-
ing lock unit communicates with KOS-ECU to unlock
the IG knob. If the steering lock unit communication
error (no response) occurs at this time, the DTC is
set.

.

TECHNICAL DESCRIPTION (COMMENT)

When the IG knob unlock communication is per-
formed by pressing the ignition push switch, if the
steering lock unit communication error (no response)
occurs, the steering lock unit is judged as abnormal.

.

TROUBLESHOOTING HINTS

• Malfunction of the key reminder switch (inte-

grated into the steering lock unit)

• Wiring harness or connector failure of CAN bus

line

• Malfunction of the KOS-ECU

KOS-ECU

KEY
REMINDER
SWITCH

Key Reminder Switch and KOS-ECU Circuit

AC708950AZ

Connector: C-05

AC708953AC

Connector: C-211

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-68

DIAGNOSIS

Required Special Tools:

• MB991958 Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicles Communication Interface (V.C.I.)

• MB991827 M.U.T.-III USB Cable

• MB991910 M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.

CAUTION

To prevent damage to scan tool (MB991958), always turn
the ignition switch to the "LOCK" (OFF) position before
connecting or disconnecting scan tool (MB991958).
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO : Repair the CAN bus line. (Refer to GROUP 54C

−

Diagnosis

P.54C-14

).

STEP 2. Check key reminder switch connector C-211 and
KOS-ECU connector C-05 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Is the key reminder switch connector C-211 and

KOS-ECU connector C-05 in good condition?
YES : Go to Step 3.
NO : Repair the defective connector.

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link
connector

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-69

STEP 3. Wiring harness check between C-211 key reminder
switch connector and C-05 KOS-ECU connector for open
circuit.
(1) Disconnect C-211 key reminder switch connector and C-05

KOS-ECU connector.

(2) Measure at the connector side of C-211 key reminder

switch connector and C-05 KOS-ECU connector.

(3) Measure the resistance between the terminals.

•

C-211 key reminder switch connector terminal No.9

−

C-05 KOS-ECU connector terminal No.5.

•

C-211 key reminder switch connector terminal No.11

−

C-05 KOS-ECU connector terminal No.31.

•

C-211 key reminder switch connector terminal No.12

−

C-05 KOS-ECU connector terminal No.4.

OK: Continuity exists (2

Ω or less)

Q: Is the check result normal?

YES : Go to Step 4.
NO (C-211 key reminder switch connector terminal No.9
− C-05 KOS-ECU connector terminal No.5.) : An open

circuit is present in the wiring harness between C-211
key reminder switch connector terminal No. 9 and
C-05 KOS-ECU connector terminal No. 5. Repair the
wiring harness.

NO (C-211 key reminder switch connector terminal
No.11

− C-05 KOS-ECU connector terminal No.31.) : An

open circuit is present in the wiring harness between
C-211 key reminder switch connector terminal No. 11
and C-05 KOS-ECU connector terminal No. 31.
Repair the wiring harness.

NO (C-211 key reminder switch connector terminal
No.12

− C-05 KOS-ECU connector terminal No.4.) : An

open circuit is present in the wiring harness between
C-211 key reminder switch connector terminal No. 12
and C-05 KOS-ECU connector terminal No. 4. Repair
the wiring harness.

AC709710 AB

Harness side: C-05

Harness side: C-211

AC709710 AC

Harness side: C-05

Harness side: C-211

AC709710 AD

Harness side: C-05

Harness side: C-211

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-70

STEP 4. Check the wiring harness between the C-211 key
reminder switch connector (terminal Nos. 9, 11, 12) and the
ground for short circuit.
(1) Disconnect C-211 key reminder switch connector, and

check the wiring harness.

(2) Check the wiring harness between C-211 key reminder

switch connector (terminal No.9) and ground

OK: No Continuity

(3) Check the wiring harness between C-211 key reminder

switch connector (terminal No.11) and ground

OK: No Continuity

(4) Check the wiring harness between C-211 key reminder

switch connector (terminal No.12) and ground

OK: No Continuity

Q: Is the wiring harness between C-211 key reminder

switch connector (terminal No. 9, 11, 12) and the ground
in good condition?
YES : Go to Step 5.
NO (key reminder switch connector C-211 terminal No.9
− ground.) : Repair the wiring harness between C-211 key

reminder switch connector (terminal No. 9) and the
ground.

NO (key reminder switch connector C-211 terminal
No.11

− ground.) : Repair the wiring harness between

C-211 key reminder switch connector (terminal No.
11) and the ground.

NO (key reminder switch connector C-211 terminal
No.12

− ground.) : Repair the wiring harness C-211 key

reminder switch connector (terminal No. 12) and the
ground.

AC709703AG

Harness side: C-211

AC709703AH

Harness side: C-211

AC709703AI

Harness side: C-211